Heating element for annealing furnaces



Sept. 7, 1937. 1., c. HAMLINK HEATING ELEMENT FOR ANNEALING FURNACES Original Filed June 6. 1935 1N VENTOR. Z AZE/VBY 6 HA ML INK ATTORNEY S Patented Sept. 7, 1937 UNITED STATES HEATING ELEMENT FOR ANNEALINGv FURNACES Lazenby C. Hamlink, Cleveland Heights, Ohio, assignor to The Gas Machinery Company, Cleveland, Ohio, a corporation of Ohio Original application June 6, 1935, S 25,250. Divided and this application 1937, Serial No. 138,771

3 Claims.

This application is a division of my pending application, Serial No. 25,250, filed June 6, 1935.

My invention relates to improvements in heating elements for annealing furnaces, and particularly to such elements that are utilized in furnaces adapted for the heat treatment or annealing of metal plates, sheets, strips, etc., in a controlled non-oxidizing atmosphere. More particularly, the invention relates to an improved heat-radiating structure in which, by the circuitous circulation of the heating gases, fewer individual radiating units, and, hence, fewer burners are required than in any other furnace of this nature, giving equally satisfactory results, with which I am acquainted.

The annexed drawing and the following description set forth in detail certain means embodying my improved heating element for annealing furnaces, and showing and describing the 20 same in association with a furnace structure,

such means constituting, however, but one of the various forms in which the principle of the invention may be embodied.

In said annexed drawing:

25 Figure l is a vertical longitudinal section of a furnace structure, including two of my improved heating elements, one at each end of the furnace,

- there being two such elements provided for each end of a complete furnace, the section of the 30 figure being indicated by the line ll, Figure 2;

and

1 section, taken in the plane indicated by the line 2--2,- Figure 1. p 3 Referring to the annexed drawing, certain feaa tures of a furnace structure are indicated, such as a base] having a foundation of insulating concrete 3 supported upon a steel plate 4, the latter being supported upon transverse I-beams 40 5 reinforced by longitudinal beams 6. Upon the aforementioned structure is adapted to be supported a movable outer cover 2, this cover 2 being provided with a base plate 29 which rests upon, and extends outwardly from, an outer shoulder portion 3?, of the insulating base portion 3. Channel members ll, which are secured to the outer faces of the insulating base shoulder 3 and are supported at the bottom by the I-beams 5 and 6 and which abut the plates 29 at the upper edge, form containers for sand seals 8 into which dip skirt portions 1 depending from the lower face of the plates 29 of the outer cover 2. A stock plate 9 is supported upon the top of the insulating base portion 3, and is of an area greater than the area of the stock It to be Figure 2 is a fragmentary transverse vertical gm No.

pril 24, 7

treated. Mounted upon an inner shoulder portion 3' of the insulating base 3, adjacently exteriorly of the stock plate 9, is a trough Ill filled with a sand seal l2 into which is adapted to dip an inner cover It which is utilized for inclosing the pack it during the heat treatment. This inner cover M permits more expeditious use of the outer cover 2 and also makes unnecessary a gas-tight outer cover 2, as is well-known to those skilled in the art.

The outer cover 2 is adapted to be lifted from the insulating shoulder 3 of the base i or replaced thereon, when necessary, for effecting the placement and removal of the pack it, or when transferring the cover 2 to another base i, all as is well-known in the art.

My improved heating elements l5, which are tubular alloy members, are located in opposite side chambers 26 of the furnace formed between the side walls 25 of the outer cover 2 and opposite side walls of the inner cover it. There are two of these heating elements iii in each chamber 26, and theyare respectively extended through and from the end walls 23 of the cover 2 and so far inwardly of the chambers 26 that each of the elements i5 is of a longitudinal dimension somewhat less than one-half the length of a chamber 26. However, each element [5 is of sinuous formation so as to provide a tortuous conduit ll for the passage of the heating medium from one end of the element I5 to the opposite end of a length much greater than the longitudinal dimension of the element. Both ends of the elements l5 are open and burners l6 are provided for firing into one end of the elements, the-opposite ends of the elements l5 opening into fiues It provided with inspirators l9. Additional burners iii are provided for firing into the elements l5 intermediate their ends. In the form of element shown in the accompanying drawing, one such additional burner i6 is provided for each element l5 and fires into the latter substantiallymidway between its ends.

The construction of the tubular steel alloy member shown in the accompanying drawing comprises substantially straight and substantially parallel terminal portions 28 and 2! and respective reentrant inner sections 22 and 22' which are substantially parallel and which lie intermediate the terminal portions 25 and 2t and communicate one with the other through an elbow portion 28. The terminal portions 28 and 2! respectively communicate with the inner sec 2i. Communicating with the reentrant section 22 at substantially the point of communication of the latter with the elbow section 28 is a sub stantially straight section 20 into the outer end of which the additional burner 16 fires. Thus, 5 there is provided a heating element having a large radiating surface, and of symmetrical formation for uniform heating thereby from end to end, together with means for firing into one end of the element and means for replenishing the element with heating medium intermediate its endsto compensate for the heat utilized in that part of the element into which the end burner fires. The construction also affords the required comparative heating suitable for the center of thevpack l3.

The ends of the elements I5, and the intermediate sections thereof, are supported in the end brick walls 23, and the terminal portions 2| and the reentrant sections 22, in the use of the 20 element illustrated, which is a use thereof in vertical position, rest upon brackets 24 anchored in the side walls 25 and projecting inwardly from the inner faces of said walls 25.

Although I have described the element I5 as 25 comprised of portions and sections 2|, 2|, 22, 22', 21, 21', 28, and 20, this has been done only for the purpose of definitely setting forth the nature of the sinuous formation in which the element is made, since, of course, the whole element l5 preferably is an integrally formed structure.

What I claim is:

I 1. A heating element for an annealing furnace consisting of a tubular steel alloy member, bumer means adapted to fire thereinto and adjacent one end thereof, said member being of sinuous formation and providing a tortuous conduit for the passage of the heating medium, said member comprising terminal portions provided respectively with reentrant inner sections, and a portion communicating with said inner sections, 'a conduit member communicating at one end with said last-mentioned portion, and burner means adapted to fire into the opposite end of said conduit member.

2. A heating element for an annealing furnace consisting of a tubular steel alloy member, bumer means adapted to fire thereinto and adjacent one end thereof, said member being of sinuous formation and providing a' tortuous conduit for the passage of the heating medium, said member comprising substantially straight terminal portions provided respectively with reentrant inner sections, said inner sections being opposed one to the other and being disposed intermediate said terminal portions, and a portion communicating with the inner ends of said reentrant sections, a conduit member communicating at one end with said last-mentioned portion, and burner means adapted to fire into the opposite end of said conduit member.

3. A heating element for an annealing furnace consisting of a tubular steel alloy member, burner means adapted to fire thereinto and adjacent one end thereof, said member being of sinuous formation and providing a tortuous conduit for the passage of the heating medium, said member comprising substantially parallel terminal portions, substantially parallel inner sections disposed intermediate said terminal portions and substantially shorter than said terminal portions,

LAZENBY C. HAMLHIK. 

